31233323221 has 4 divisors (see below), whose sum is σ = 31242147244. Its totient is φ = 31224499200.

The previous prime is 31233323167. The next prime is 31233323243. The reversal of 31233323221 is 12232333213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12232333213 = 1109 ⋅11030057.

It can be written as a sum of positive squares in 2 ways, for example, as 22329324900 + 8903998321 = 149430^2 + 94361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31233323221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31233323291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4406700 + ... + 4413781.

It is an arithmetic number, because the mean of its divisors is an integer number (7810536811).

Almost surely, 2^31233323221 is an apocalyptic number.

It is an amenable number.

31233323221 is a deficient number, since it is larger than the sum of its proper divisors (8824023).

31233323221 is an equidigital number, since it uses as much as digits as its factorization.

31233323221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8824022.

The product of its digits is 3888, while the sum is 25.

Adding to 31233323221 its reverse (12232333213), we get a palindrome (43465656434).

The spelling of 31233323221 in words is "thirty-one billion, two hundred thirty-three million, three hundred twenty-three thousand, two hundred twenty-one".